PART I.  Multiple Choice

1.  c

2.  b

3.  a

4.  e

5.  b

6.  d

7.  b

8.  c

9.  d

10.  a

 

PART II.  Problem Solving

Question 1.

Plan A

 

Plan B

 

Plan A would cost $165,400, while Plan B would cost $167,400. In this case it is cheaper to vary work force than to use overtime (i.e., use Plan A).

 

Question 2.

a.   The EOQ is 194.

b.   Total cost at Q=194 is $774.60

c.   The warehouse will hold only 600/4 = 150 containers.

      The annual cost at Q=150 is 100 x 5 + 75 x 4 = $800.

d.     C&A would consider paying up to $25.40 ($800-774.60) for a year's rental of enough space to store 44 additional containers.

e.      Total number of orders placed in a year = 15000/194 = 78

Time between orders = 300/78 = 3.8 days

If lead time is 7 days (> time between orders), reorder point = daily demand x lead time – EOQ = 15000/300 x 7 – 194 = 156

 

   f.

g.

 

h.  EPQ = 613 units

i.   Qmax = EPQ(1-d/p) = 154 units

          Length of production run = 613/20000 x 300 = 10 days

          Total number of production run = 15000/613 = 25

          Time between production run = 300/25 = 12 days

          Length of time with no production = 12-10 = 2 days

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

j.  TC(EOQ) = 2 x (15000/194x5) + 100x15000 = 1500775

    TC(EPQ) = 2 x (15000/613x10) + 80x15000 = 1200490

    C&A should produce

 

k.  EOQ(item cost = $95) = 199 infeasible

     TC(EOQ) = 1500775

     TC(Q=200) = ordering + holding + item = 375+ 380 + 1425000 = 1425755

     C&A should take the discount

 

Question 3.

a.

 

 

b.

Activity

a

m

b

Expected

Time

ES

EF

LS

LF

Slack

Variance

A

4

7

10

7

0

7

0

7

0

1

B

2

8

20

9

7

16

9

18

2

9

C

8

12

16

12

7

19

7

19

0

1.777778

D

1

2

3

2

16

18

18

20

2

0.111111

E

6

8

22

10

19

29

20

30

1

7.111111

F

2

3

4

3

19

22

19

22

0

0.111111

G

2

2

2

2

22

24

28

30

6

0

H

6

8

10

8

22

30

22

30

0

0.444444

I

4

8

12

8

30

38

30

38

0

1.777778

J

1

2

3

2

38

40

38

40

0

0.111111

 

        The critical path is A-C-F-H-I-J

 

c.     LF of J = 40 Weeks

 

d.     1+1.78+.11+.44+1.78+.11 = 5.22

 

e.

       

        The probability from the standard normal table is approximately 81%

 

f.     A 95% confidence interval gives a z-value of 1.64

         weeks